SALT LAKE CITY — A diplomat to the core, Jon Huntsman is well known here as a likable guy who prefers compromise to combativeness. Niceness is such a strong part of his persona that the Republican pledged to run a civil campaign for president.

"He genuinely wants to please people, and he gets along with everyone," says Olene Walker, a Republican who preceded Huntsman as Utah governor.

But now, as Huntsman struggles against better-known opponents, he is both subtly and directly criticizing GOP front-runner Mitt Romney as well as the Democrat who named him U.S. ambassador to China just a few years ago, President Barack Obama.

The shift in tone comes as polls show Huntsman in single digits nationally and in key states, and it follows his decision to change campaign managers. Advisers over the past few weeks have been telling Huntsman that he must engage Romney and Obama to boost his prospects of winning the GOP nomination.

He's obliged.

While in South Carolina recently, Huntsman jabbed at Romney's record, saying Utah led the way on job creation and urging his audience to compare it to Massachusetts' standing: "Not first, but 47th." And last week in New Hampshire, he called Obama "a good man" and "earnest." But, he added, "He's fundamentally failed us."

It's an uncomfortable political role for Huntsman, who has prided himself on his diplomatic skills and is rarely disliked by anyone, even those who disagree with him politically. In part, that's because he has never faced a strong challenge for political office, but it also speaks to his personality.

Known in Utah for his 'charm'
Republicans and Democrats alike in Utah roundly describe Huntsman as a leader who always sought the middle ground and never resorted to personal attacks to gain the upper hand.

"He wasn't an ideologue, and he empathized with a lot of different points of views," said Salt Lake City Mayor Ralph Becker, who was the Utah House minority leader during most of Huntsman time as governor. "He's the kind of leader we want. He's inclusive, he's charming and he's got strong diplomatic skills."

As governor, Huntsman was almost as popular with Democrats as he was with those in his own party, which made him practically invincible when he ran for re-election in 2008 in a strongly conservative state.

His Democratic opponent, Bob Springmeyer, said Huntsman never did anything publicly or privately that suggested he was anything but genuine. "The nice-guy image, the diplomatic personality is legitimate," he said.

Thus, as he increases his criticism of his White House rivals, Huntsman risks undermining his authenticity and turning off GOP primary voters. That may explain why he's trying to contrast himself with his rivals without appearing negative. It's as if he'd rather let voters read between the lines of his criticism than castigate his opponents by name.

"A lot of people run from their record. We're running on our record," Huntsman told college Republicans late Friday in Washington.

He didn't mention Romney, but the target of his comment was clear, and his aides acknowledged that he was referring to the former Massachusetts governor who has downplayed certain parts of his record that don't sit well with conservatives.

His campaign aides dispute the notion that Huntsman has shifted to a more negative tone even as they mercilessly assail his opponents — Romney in particular — on social networking sites and in media interviews.

Among those aides is Tim Miller. The Huntsman spokesman argued that Huntsman wasn't criticizing his opponents in "ways that are petty or engaging in name calling." Rather, he said, Huntsman was simply contrasting his record with those of others.

"Voters want a candidate with a vision for the county. They don't want an angry president," said Miller.

Huntsman, for his part, explained his approach this way in a recent interview with CBS: "Civility can coexist with the facts."

"In a race, you've got to point out your differences, you've got to put your record on the table," he said. "It's the personal attacks that I think Americans hate so much about politics these days. Stick to the issues. You can talk about the issues and draw your differences."

But can Huntsman do that without breaking his civility promise? Has he already broken it?

"The attacks so far were civil. They bordered on classic political attacks, but didn't get there," said Alex Slater, a Washington-based Democratic consultant. "But I can't believe they won't continue to sharpen. I don't think they can maintain the civility pledge."

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